Apparatus for and method of making roads.



J. A. JOHNSTON.

APPARATUS FOR AND METHOD OF MAKING ROADS.

APPLICATION HLED APR.2. 19M.

Patented Nov. 2

mates.

' Making Roads,

Jenn a. Jonnsron, or srnmsrrnitn, nassacnusnrrsp To all whom itmay concern:

Be it known that I, JOHN A.

JoHNs'roN, a citizen of the United States,

residing at Springfield, in the county of Hampden and State of Massachusetts, have invented a new and useful Apparatus for and Method of of which the, following is a specification. I i

The principal objects of this invention are to provide for making a road with an even and uniform wearing layer; and to provide an improved apparatus for accomplishing r v l this result.

Reference is to be had to the accompanying drawings in which Figure l is a plan of an apparatus for carrying out this invention; Fig. 2 is aside .elevation thereof; and Fig. 3 is a longitudinal hand. Therefore each mixing method where sectional view of a line 3-3of:- Fig. -1. I

There are two general processes of distributing a layer of combined bitumen. and sand or small stones to furnish a Wearing surface to a road bed. In the penetration method the fine stone is. placed first on the road bed and the bltumen poured overit. Inequalities in the sizes of the stone fragments result in irregularity inthe voids between the stone and causeanunequal penetration of the matrix. As it is impracticable to cover the bitumen immediately it cannot be rolled until it is so cool that it is no longer molten and there must be necessarily a lack of homogeneity. On account of the inequality of the voids, part of thebitumen, namely, that lying in the large voids, may be much softer than when the rolling takes place. This adds to this difficulty and the surface of such a road, therefore,- is relatively uneven and'bunchy. Parts of it contain more bitumenthan other parts and r it necessarily wears unevenly. The other method referred to is the so-oalled the matrix gate materials are mixed by hand or mechanical means before placing on the road. In this case the mixture is distributed by shovelful is a separate mass and the most extreme care is necessary to rake over these separated masses to prevent making bunches. In. addition to this an appreciable amount of time elapses before the roller can pass ower this mass for part ofthe same on the pressing and the bitumen is therefore socool that the mixture cannot be thoroughly compacted.

Specification of Letters Patent. I 'pm Nmvw, 1915a v I .1 w p u Application filed April 2, 1914. Serial No. 829,148. l i l I is distributed that in the small voids.

' ble hose 113'.

and aggre- C gregate oyer an inclined-plane layerion the road surface.

stood of course thatthis distributlon can 1 0 'arrnnarus iron nnniunrnon or MAKING nouns.

uniform penetration of every crack and cranny of thesurface over which it is spread and to apply it'to a uniform surface so that it will be uniformly spread upon it. In-this way the greatest possible adhesion to that surface is secured. Furthermore, the bituminous 65 matrix thus spread is covered mstantaneously,

while stillin a thoroughly molten condition with-an aggregate of stone or sand. This by mechanical appliances in an absolutely uniform manner. both'the matrix and the aggregate can be left finally in, absolutely uniform layers and as no-bitumen is left uncovered 'aroller can follow it immediately and force the aggregate material into the bitumen while the'latter is-still moltenthus insuring thorough adhesion of the matrix to the aggregate and foundation, giving therefore a homogeneous and uniform wearing surface. These results are extremely by this invention they are secured in an extremely simple manner which does not add i to the cost of applying. the layer but in fact decreases it.

The method of application'i s being carried out by certain mechanism,

some of.w hich is well known in the art.

First, an ordinary steam roadiroller or other vehicle A isshown constituting the r notive powergfor drawing the rest ofthe apparatus. W

On the rear this carries a cross bar 10 behind which trail res and a spreader alongslde each other. This tank-wagon is of ordinary construction and P at need'not be described in detailbut is vided with a discharge pipe 11 at the connected thr ugh the valve 12 with aflexi his hose is connected witha distributing pipe 14 carried by the spreader his mechanism substantially the same as that used in a well known type of manure Spreaders, that is, it is provided with acarrier 1-bringing the sand or fine stoneagwhich it is carried up around a spreading, cylinder 17. This carries the aggregatematerialr'up and distributes itin a unlform It will be undertake place from the rear of the spreader or from any point'at the bottom according to In this way 70 important in practice and M illustrateda w ectively, a tank wagon B p spreader is shown as comprising mm at 16 from 05 the type of spreader "employed, the-details f the spreading vapparatus not being a part of this invention, but it always spreads the a aggregate material behind the bitumen and consequently on the fresh surface thereof.

The pipe 14 is provided with a pair of hooks 20 which arehung over a shaft 21 on the spreader so that this pipe depends therefrom and is located in position in front of. the continuous stream of aggregate mate- ;"rial -so that it will distribute a layer of molten bitumen directly in front ofthe same. i i

,The tank wagon, being connected with the distributing pipe l t by the flexible connection 13, need not be kept ina definite position behind the roller but it is desired to steer the spreader so that it may distribute B preferably under pressure is controlled from the seat of thespreader C by a valve 27. Thisis allowed to operate when the spreader is inv operation and 'it will be seen i that molten bitumen is applied to the road surface sofas to penetrate into the top of it and leave a umform layer. This is immediately followed by a layer of sand or small stones which completely cover the molten bitumen and leave a surface over which a road roller can pass immediately. By pass ing the roller over it the aggregate material is forced into the molten bitumen while the same is in its best condition for receiving it.-

Mpreover, the bitumen has previously been forced into the surface of the road bed to the greatest extent possible by spraying. In this way not only is a perfectly uniform surface secured but the adhesion of the bitumi- "nous layer both tothe roadbed and to the aggregate material is insured without fail.

There is-no occasion for securingany uneven laying of either material and no chance 'for any permanent inequality of voids on t the cooling of the different parts of the bitumen, but on the other hand the materials are in the first place. laid in their final uniform condition and do not have to bespread out or evened up subsequently. This is a great advantage not only in the ease of laying but especially in the durability of the road bed itself, and the protectionof the surface on which this wearing layer is placed. f With it will be seen that a very essential feature is that I provide'for immediately covering the my method of making the road bed,

liquid matrix material, the aggregate material being continuously applied to the liquid materlal as fast ash; is spread upon the road a bed surface, thereby not only avoiding all mucking up of the tools and vehicles as well as the feet of the workmen and draft animals, but also avoiding the objectionable hardening or setting of the molten material that always occurs when this type of road bed is made, by the usual manual methods. In other words, an important feature of my invention is that at no time during the carrying out of my method is there anything more than a small area of the liquid matrix materialiexposed, and this exposure lasts such a short time (but a fraction of a second ordinarily) that it is entirely negligible. In this way, practically the entire roadway is left free to be used by the workmen and road-building vehicles'as well .as by passing vehicles, thereby rendering it unnecessary to entirely closev the roadway to trafiic and also 'ving the workmen ample room for performing the various duties incident to work of this character. Withno other method of building this type of road bed that I am aware of can the work be done so expeditiously and cleanly and with so little disturbance to traffic as with my method.

Another important advantage is that the aggregate-carrying vehicle 'may be detached from the plant and taken back to the stone or gravel pile for another load without putting the plant out of. operation, since another vehicle may be kept at hand to replace the one sent back to the pile. It will therefore be seen that with several of these aggregatecarrying vehicles in use, ,the plant may be kept continuously in operation at a considerable distance from the stone pile. This is very important, since it is impracticableto carry in a single load any considerable quantity of the aggregate material, while it is entirely possible to haul a tank vehicle of suflicient capacity to last a considerable time. To disconnect the aggregate vehicle it is simply necessary to lift the sprayer pipe off its supports on that vehicle and swing it upwardly or to one side out of the way and i then disconnect the coupling rod 24 from the draft rigging of the plant.

' Although I have illustrated and described a certain preferred machine which it is desired to use, I am aware of the fact that other devices or machines can be used in place of them and modifications in details of a construction can be made without departing from the scope of the invention as expressed in the claims, therefore I do not wish to be limited in these respects, but l What I do claim is 1. The method herein described of road building consisting in progressively and forcibly projecting upon and into the surface of the road bed alayer of liquid matrix gregate material upon said matrix, gregate material being deep enough to so vthe matrix material for any appreciable with aroller,

rpad bed, 7 applied to the matrix material While the vehicle and in. front of the material of a kind adapted to set or harden upon exposure and immediately and pro-- gressively spreading a uniform layer of agthis agcompletely cover the matrix material to form a substantial part of the body of the whereby the aggregate material is same is still in a liquid state and whereby also exposure of any considerable area of length of time is avoided, and subsequently compacting the aggregate material into the matrix. L

2. In a portable road building plant, the

combination of a tank vehicle and an aggregate vehicle detachably connected to gether, said aggregate vehicle being provided with means for discharging the ag gregate material at its rear end, a matrixspraying pipe flem'bly connected to the-tank vehicle, and means for removably supporting said spraying pipe behind the aggregate discharging stream of aggregate material, whereby the spreader being provided with a spraying pipe, a flexible connection between the outlet pipeof the tank car and said spraying pipe, and means on said spreader for spreading sand or stonecaggregate material on the road bed pipe.

. 4. In an apparatusfor making roads, the combination with a propelling vehicle, of a tank car trailing behind the same, 'a spreaderalsotrailing along behind the vehicle and alongside the tank car, a spray '40 just at the rear of said spraying 4 'ingpipe connected with the tank car, and

.ble connection, means for supporting said spraying pipe may be disconnected from the aggregate vehicle and swung aside and the aggregate vehicle detached, for the purpose set forth. 3.' In an apparatus for applying a wearng surface to a road bed, the combination the same,

being pro of a tank car trailing behind and a spreader trailing behind the roller alongside the tank car, said tank-oar vided with an outlet pipe, said means on said spreader for spreading aggregate material on the road bed just at the rear of said spraying pipe. l

5. In a-portableroad building plant, a

tank vehicle and an aggregate-carrying vehicle and means for detachably connecting.

them together so that they may travel as a pair or separately, a spray, pipe attached to the tank vehicle and provided with a flexispray pipe at the rear of the aggregate vehole, and means on the aggregate vehicle 

